NON-INTRUSIVE FIBER OPTIC PRESSURE SENSOR FOR MEASURING UNSTEADY PRESSURES WITHIN A PIPE

摘要

Non-intrusive pressure sensors (14-18) for measuring unsteady pressures with in a pipe (12) include an optical fiber (10) wrapped in coils (20-24) around th e circumference of the pipe (12). The length or change in the length of the coils (20-24) is indicative of the unsteady pressure in the pipe. Bragg gratings (310-324) impressed in the fiber (10) may be used having reflection wavelength .lambda. that relate to the unsteady pressure in the pipe. One or more of sensors (14-18) may be axially distributed along the fiber (10) usin g wavelength division multiplexing and/or time division multiplexing.